Method op and apparatus for producing blasts of heated air



vv. w. NENP AND w. H. vAN HORN.

METHOD 0F AND APPARATUS FOR PRODUCING BLASTS 0F HEATED AIR.

APPLICATION FILED JUNE 23.1916.

1,31 1,235. I PatenteJuly 29, 3919.

`with which a wide ran e of temperatures,

-` UruiTED sTATEs PATENT oEEIoE.

' WILLIAM WALLACE KEMP AND WILLIAM H. VAN HORN, 0F BALTIMORE, MARYLAND.

METHOD 0F AND APPARATUS FOR PRODUCINGy BLASTS OFVHEATED Specification of Letters Patent.

Patenten .rely 2e, Tere.

Application led June 23, 1916. Serial No. 105,525.

land, have invented new and useful Improvements in Methods of and Apparatus for Producing Blasts of Heated Air, of

which the following is a specification.

This invention relates to, a method of and apparatus for heating, and has as one of its o ]eets to produce a blast of heated an' which is discharged from the heating device under a relatively' hi h pressure, and by means of which a high egree of heat may be obtained. I-

A further object of the invention is to produce a hot air blast without employing a blower o r compressor'for' forcing the air to be heated 'through the apparatus, and

varying from a relative y low de ee to` a relatively hi hl degree, may be obtained, and which, there ore, is adaptable of a great variet of uses. Our improved heater ma'y be use to heat a` Ylarge volume pf air, and the temperature to whlch the air 1s heated is always under perfect control, and these features make the device particularly adaptable v for use in apparatus where drying operations are carried out, but, of course, it may be employed for heating purposes generally.

The above and other objects of our invention are Vobtained by the structure described inthe following specification and illustrated in the accompanying drawings, and wherein: f Figure lis a longitudinal section through one form of our improved blast heater.

Fig. 2 is a view similar to 1 but showin a modification of our device:

'ig. 3 is a longitudinal sectlon through Y another embodiment of this invention.

Referring to the drawings, wherein like numerals represent like parts in the several views, 10 designates the burner or burner tip which may be of any suitable .or improved construction, and to which is connected a' a cock 12, the internal construction of which is not disclosed, as it lforms no artof our invent1on. The cock 1s provi ed with 'a handle 13 which may be turned to open or close the pipe and. regulate the flow of fuel therethroughi and, in the present instance,

the cock is cisclosedas having a plate 14 provlded with a suitable scale thereon, and a andle wlth a pointer 15 movin over the scale to designate the position oft e cock.

' The burner 10 extends a slight distance i into one end of an o en-ended tube 16 which* may be of any suit. le proportions depending upon the pressure with which the fuel is discharged from the burner and other conditions. Upon ignition of the gases issuing from the burner, 4Yatrr'iospherie air is entrained at-the burner end of the tube 16 and the heated air issuing from the outer end of the tube 16 may be discharged directly inte the machine, a paratus, or room to be heated, or it may e distributed by any suitable means to the place where it is to be used for drying or heatin 't In Fig.' 2, we have shown t e structure illustrated in Fig. 1 as having a second tube 17 into which the Outer end of the first tube 16 projects to a slight distance, and, in this instance, in addition to the air entrained by the rst tube, air is drawn into the second tube about theoutlet end of the first tube.

In Fig. 3, means for controlling the amount of air entrained intol the o ening between the adjacent ends of the tu es 16 and 17 is provided, and while this means may be varied in construction, We have shown. in .the present embodiment, the tube'- `17 .as'havlng a tapering skirt 18 provided with suitable ports 19, and about the skirt 18 is a damper comprising a conical-shapedv the heated air issuing from the outer end of the larger tube'l? may be regulated or controlled either by operating the damper to vary the amount of air entrained by the larger tube, or by turning the cock 12 to admit more or less fuel to the burner. 4If a lower temperature and a greater' volume of airare desired, the damper 20 is turned to -bring the ports in the damper and skirt 18 into registry, thus permitting a larger amount of air to be entrained by the outer tube, and I-if a higher temperature and less volume is desired, the damper is turned to lclose the ports 19 and thus prevent the larger tube from 'entraining air.

'l When it is desired 'to place the device in operation, the handle 13 is turned to the proper extent to admit the flow of `fuel through the pipe 11 to the burner 10. The fuel issuing from the burner is ignited and as the fuel is under pressure, a Haine is shot into the tube 16, as is shown in Fig. 1. The heated products of combustion expand and are forced to the outer end of the tube by the relatively high pressure with which the incoming fuel is forced through the burner,

and this causes a suction action at the burner v end of tube 16, which draws or entraine atmospheric air into the tube about the burner, as designated by the arrows. The

fuel upon ignition, and the air upon being heated vgreatly expand, and this action toether with the force with which the fuel is injected into the tube 16 forces the air with considerable velocity from the tube, and, at the same time, air is entrained or sucked into the tube at the burner end by the rarefaction thus created. Thus atmospheric air is drawn into the tube at one end, ,becomes thoroughly mixed with the products of oomv heated air and products of combustion are discharged from the other end of the tube in a highly heated condition andunder considerable pressure.

The tube 16 may be placed in any position, and where desirable it may be inclined downwardly from its burner end, the pressure of the fuel together with the expansion of the heated air and products ofcombustion being sufiicient to force the heated air through the tube and overcome any upward draft. We have found that although the tube is inclined downwardly and is nine or ten feet in length, a blast of hot air can be discharged from the lower end of the tube at a tempera-v ture of 900 to 1000o F. and at considerable velocity. Any suitable fuel may be supplied to 'the burner so long as such fuel is under highpressure, and natural or artificial gas or the like may be used, but we have found that admira-ble resul-ts may be obtained by supplying an explosive mixture to the burner,

A and while any suitable type of air and gas mixing device may be employed for this purpose, we refer to the apparatus shown and described in the patent to W. H. Van Horn and W. Kemp, No. 1,141,466, granted June 1, 1915. lin this apparatus, the air and gas' are mixed in proper proportions, so that the mixture is self-sustaining; that is, lthe mixture contains sufficient oxygen for complete combustion of the gas, and Ithus no outside supporter of combustion is necessary, Where a mixing device such as described in said patent is' connected to the pipe 11 to supply a self-sustaining mixture minder Apressure to the burner, the vchemical characteristics of the entrained atmospheric air are -in no way modified in passing bustion, and is heated thereby, and Ytheplying a completely combustible mixture Mwill be mixed with a supplemental body O'f terasse through the heater, the air4 being merely drawn into the tube, heated by the flame of the burner, mixed with the products of combustion, and propelled through' and from the tube with considerable velocity due 70 to--the force with which the explosivemixture is injected into the tube. Byusing'a self-sustaining mixture such, as described, L we have found that an intense heat may be obtained, and that the device is -very cc0- 75 nomical in the consumption of fuel, the explosive mixtre being completely consumed, and no residueof solid products of combustion remaining. All obnoxious odors are eliminated and the temperature of the air to 10e heated is always under perfect con- This invention is. susceptible of various other modifications and changesl` which would be within the spiritv of the invention, without departing from the scope of the following claims. 'x

What is claimed isz v 1'. In an apparatus for producing a blast of'heated air, the combination of a conduit, 90 a burner projecting into one end of the conduit and separated from the side walls thereof by an annular air space, and means for y supplying a completely combustible mixture under pressure to the burner, the `parts being so related that the iiame or burning gases from the 'burner will ibe confined entirely within the-conduit 'and that the ignited mxture discharged from-the burner'under pres sure will entrain a body of air 'supplemental to the combustible: mixture thro h the space surrounding the burner and Iorce it with` the non-flaming products of combustion from the other end of the conduit with considerable velocity.

2. In an apparatus for prod-ucinga blast. of heated air, thev combination of a conduit, a burner projecting into one end of the con-v duit and separated from the side walls thereof by an annular air space, means for sup-,110

under pressure to theburner, and a second conduit of greater diameter than and surrounding andextending forward from the burner containing conduit and open at both ends, the-burner containing conduit being ofsuch length that-:burning gas from the burner will not .be projected beyond the end thereof, whereby the products of combustion air drawn through the rear ends of both tuibes, and chemical characteristics of which wll'l'notbe modified in the tubes, and dis- 'char ed with considerable velocity.

3: ihe method of heating herein, de-I 1425 scribed which consists in -admixing a combustible gas and a sup orter of combustion an such quantities that t e amount ofthe latter present will support completel combustion ofthe gas, dischargingthe pfremxed un open ended tube,l igniting said mixture Iund entrajning air into the tube Withoutl causing combustion of said entrained air, and which entrained air is mixed with the hot products `of'oombu'stion from the flame and forced through and from the tube with considerable velocity.

4. xrThe method of heating herein described which consists in admixing air and 4gas in such quantities that suicient air is presen-t tosupport complete combustion of the gas, discharging the premixed self-sustaining mixture under pressure into an open ended tube, igniting said mixture, en-

training air into the es@ which ene-eines air is mixed with Ithe hot products of oom- 'lbustion from the Home without being burned and forced through and' from the tube' with considerable velocity, and also en- ;treining air at the outlet end of the rst tube into a'seeond tube.

In testimony whereof we have hereunto set our hands in presence of two subscribing Witnesses.

WILLIAM WALLACE KER@.

WILLIAM H. VAN HRN. Witnesses:

H. G. BISHOP,

MARY Uns. 

